Contents

Summary

A prerequisite for the use of SIMIS, is that the SIM card must be functional. A physically damaged, broken or dirty SIM may not function correctly, resulting in the recovery of corrupted data, or no data at all. In the forensic data recovery environment, SIM's will be presented in a variety of different conditions, ranging from good, but lightly soiled, through blood soaked to physically broken. Lightly soiled and blood soaked SIM's may be cleaned using appropriate methods, ensuring that the SIM is not further damaged taking care to preserve surface printing where possible.

However, physically damaged or broken SIM's require more specialised processing to produce a viable SIM for data recovery purposes. Crownhill has extensive experience in the area of SIM data recovery through its activity in the SIM manufacturing process. Crownhill works directly with the SIM silicon manufacturers and SIM card manufacturers. Processes developed to aid fault analysis and qualitative measurements are an invaluable advantage when attempting to repair and recover data from physically damaged SIM modules.

Crownhill have invested in purpose-built laboratory facilities to provide professional card cleaning, data recovery and card repair service. Based in discrete, secure premises, Crownhill can provide the full compliment of services required to clean, repair and recover data from damaged SIM's. Drawing on its own expertise and relationships with Card manufacturers and silicon vendors world-wide, Crownhill have created a centre of excellence for this specialised work. An overview of the procedures can be found here

Where a SIM is thought to be functional, Crownhill can provide a SIM cleaning service. Blood, soot, general soiling and body fluids are handled in an environmentally secure fashion, relieving the client of responsibility for Bio Hazards and other Health and Safety issues. Cleaned SIM's are returned without undue delay, ready for data recovery by the client. Cleaning by Crownhill must be carried out after the SIM has been pre-processed for any physical evidence required, such as Photography and DNA sampling.
Data Recovery Process

Data Recovery Process

If our findings suggest that data recovery is likely to be possible, the SIM may further examined by real time X-ray, to determine the extent of the damage. Specifically we will be looking for broken or damaged wire bonds, detachment of the silicon die and possible fractures of the die.

Decapsulation

Where a damaged bond wire(s) is clearly identified and if there is no obvious damage to the silicon die, the die encapsulation can be removed. The de-capsulation process requires a great deal of skill and the use of proprietary mixes of aggressive solvents and/or acids. The exact process used depends upon the.

Testing

After de-capsulation, further electrical tests are carried out to confirm the viability of the recovered silicon die. The die bonding pads are then probed and once electrical connection is established, the silicon is accessed and the sim data recovered using proprietary software.

X-Rays

Real time X-ray examination is used to confirm the conclusions drawn from the preceding Physical, Optical and Electrical tests. X-ray examination is only undertaken where the integrity of the silicon die is thought to be uncompromised.